What is the subject of the heart to heart discussion? If it is about a family member, you could be sharing a photo album while you talk. If it is about a girl friend, you could be twirling a ring in your fingers while you talk. If it is about auto mechanics, you could be wiping your hands with a dirty rag.
The idea is to pick something from the subject of the discussion and find a prop to highlight that something. The manner in which you interact with the item can also set the mood for the discussion. If you are impatiently turning pages of a photo album while talking, that says something different from studying the photos carefully on each page before turning them. Tossing the ring back and forth from hand to hand can show nervousness or excited anticipation. Rubbing the ring with a distant look in your eyes can convey a sense of loss. Wiping your hands could mean you got interrupted while fixing the car or it could mean you want to clean yours so you can shake the other person's hand as a way of thanking them for something.
You could be tilting your chair back and forth while talking, or you could be carefully rubbing the table with your hands, or drumming your fingers impatiently, or hammering the table with your fist, etc.
Get the idea?